(a) Technical Field
Embodiments of the present invention relate to a display device including a touch sensor and a driving method thereof.
(b) Description of the Related Art
A flat panel display such as a liquid crystal display (LCD), an organic light emitting diode display (OLED display) and an electrophoretic display includes a field generating electrode and an electro-optical active layer. The liquid crystal display includes a liquid crystal layer as an electro-optical active layer, the organic light emitting diode display includes an organic emission layer as an electro-optical active layer, and the electrophoretic display may include charged particles as an electro-optical active layer. The field generating electrode is connected to a switching element such as a thin film transistor and is applied with a data signal and the electro-optical active layer converts the data signal into an optical signal to display an image.
Recently, in addition to a function of displaying an image, the flat panel display may have a touch sensing function which allows interaction with a user. When a user writes a letter or draws a picture on a screen by touching a finger or a touch pen, the touch sensing function detects a change in a pressure, a charge, or light which is applied to the screen by a display device to find out touch information such as occurrence and position of touch. The display device may be operated based on the touch information.
Such a touch sensing function may be implemented by a touch sensor. The touch sensor may be classified into a resistive type, a capacitive type, an electro-magnetic type (EM) or an optical type in accordance with methods used to sense the touch.
The capacitive type touch sensor includes a sensing capacitor and detects a touch using a change in a capacitance of the sensing capacitor when a conductor such as a finger approaches or contacts the sensor.
However, in order to install the sensor in the display device, an additional circuit which is formed on an inner surface or an outer surface of the display device may require which reduce an aperture ratio and transmittance of the display device.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.